Nanotechnology holds great promise for the early detection and treatment of cancer. The ability to both detect and follow the initiation and progression of cancer without biopsy, surgery, or other invasive techniques should lead to lower costs and higher quality of life. The goal of this proposal is to develop viral nanoparticles (VNPs) as platforms for combination tumor targeting and imaging agents in vivo. Our multidisciplinary team combines molecular biology, structure, chemistry and in vivo biology to attack this problem. In this proposal we will study two well-characterized viruses: a plant virus, cowpea mosaic virus (CPMV);and an insect virus, flockhouse virus (FHV). The accumulated knowledge of the structure, function, assembly, genome packaging, chemical attachment, and in vivo bioavailability of FHV and CPMV, developed in the co-investigators'laboratories, makes these viruses ideal candidates for such platform development. We will test the ability of tumor-specific VNPs to attack tumor cells in vitro and in vivo, and study mechanisms of uptake of VNPs into cells. We will also package anti-tumor compounds and inhibitory genes inside the particles to facilitate tumor destruction. Finally we will test the ability of our VNPs to detect and destroy tumors in vivo. These studies will make a significant contribution to the development of improved tumor targeting and imaging nanotechnologies.